In many fields such as environmental monitoring and chemical analysis, online pre concentration instruments play a key role as they can efficiently enrich low concentration samples, laying a solid foundation for subsequent precise detection. However, under continuous high-frequency operation, various faults occur from time to time. Timely and accurate diagnosis and repair are key to ensuring the reliability of experimental data and production continuity. This article will delve into common faults and corresponding solutions.

1、 Abnormal pneumatic system

1. Leakage problem

This isOnline Pre ConcentratorAn easily noticeable malfunction. Once there is a gas leak, it not only affects the concentration efficiency, but may also cause the leakage of toxic and harmful gases. It is often caused by aging and cracking of pipelines, as well as poor sealing of joints. During daily inspections, soap and water can be used to apply to suspicious areas and observe for any bubbles emerging to lock the leak point; For small sand holes, electronic leak detectors can accurately sound warnings. When handling, replace the damaged pipe section, use suitable materials to improve weather resistance, tighten loose joints or replace O-rings to enhance sealing.

2. Unstable airflow

Manifested as large fluctuations in traffic and fluctuating readings. The root cause lies in the failure of the pressure reducing valve, which cannot maintain a constant output pressure; Or the filter may be clogged, hindering the smooth passage of gas. First, check if the pointer on the pressure reducing valve dial is stable. If calibration is ineffective, replace it with a new one; Disassemble all levels of filters, replace dirty filter elements, and if necessary, install a pre stabilizing device to buffer sudden changes in air pressure.

##2、 Temperature control deviation

1. Slow heating up

Insufficient power of heating elements and inaccurate temperature measurement of thermocouples often lead to this situation. Compare the actual temperature with an infrared thermometer. If it is far below the set value, check if the heating wire is broken and replace it with a new one of the same specifications; The displacement of thermocouple position can also mislead temperature control. Re fix it to the appropriate contact position to ensure the feedback of true room temperature.

2. Overheating and loss of control

The malfunction of the thermostat and the adhesion of the relay will cause continuous heating. Short circuit the temperature control circuit, test the on/off status of the relay, and replace it if it is damaged; Upgrade the intelligent temperature control module, integrate PID algorithm, finely adjust power, and prevent overshoot and overheating.

3、 Poor cooling effect

Dust accumulation in the condenser tube and refrigerant leakage are the main causes. After long-term operation, dust and fluff will cover the heat dissipation fins, reducing the heat exchange rate. Regular compressed air blowing can restore smoothness; The refrigerant leakage is relatively concealed. Apply fluorescent leak detector along the pipeline, find the leakage hole under UV light irradiation, repair welding, vacuum fill with new refrigerant.

4、 Data transmission interruption

Poor contact is common in communication lines, such as plugging and unplugging Ethernet and serial cables, and cleaning the gold fingers; Software configuration errors may also occur. Check parameters such as IP address and baud rate, restart the acquisition program, and reconnect the device.

In short, when facing the malfunction of the online pre concentration instrument, calmly investigate and follow the above methods, most problems can be easily solved, allowing the instrument to quickly return to the right track and safeguard scientific research and production.